A mesh network is a wireless network that supports multi-hop transmission. The mesh technology is applicable to interconnection between infrastructures, between home appliances, and between user equipment and infrastructure. For interconnection between infrastructures, the mesh networking mode provides better error tolerance performance than cellular coverage. A Hybrid Wireless Mesh Protocol (HWMP) is a routing protocol in a mesh network. This routing protocol combines the proactive and reactive routing protocols to apply to a wireless mesh network whose topology is relatively static and a network whose topology is changed dynamically.
The process of creating a path by the HWMP is as follows: The HWMP routing protocol broadcasts a gateway notification message through a gateway node, also known as root node. This notification message carries the address, sequence number, and metric of the gateway. A non-gateway node in the network receives this gateway notification message, selects a latest sequence number and optimal metric of the gateway, and creates a path to the gateway. The non-gateway node unicasts a routing request that carries the information such as address and sequence number of the node to establish a downlink path to the gateway and forwards the gateway notification message. Another non-gateway node receives the routing request, creates a path to the source node in the routing request, and continues to unicast the routing request to the gateway node carried in the routing request. The gateway node receives the routing request, creates a path to the source node in the routing request, and sends a route reply. An intermediate forwarding node (non-destination node) receives the route reply, verifies the path created when receiving the gateway notification message, and continues to unicast the route reply. The destination node receives the route reply, and verifies the path information.
In a mesh network with multiple gateways, all non-gateway mesh nodes can have paths to each gateway. If no balancing policies are implemented between multiple gateways or paths, the load on nodes in the network is unbalanced. Consequently, partial nodes (including gateway nodes) may be congested while the resources on the other nodes are not efficiently utilized.